docs: def countryccys():
      '''
      Create a dictionary with keys given by countries ISO codes and values
      given by their currencies
      '''
      global _country_ccys
      if not _country_ccys:
          v = {}
          _country_ccys = v
          ccys = currencydb()
          for c in eurozone:
              v[c] = 'EUR'
          for c in ccys.values():
              if c.default_country:
                  v[c.default_country] = c.code
      return _country_ccys